My hubby calls mine a sewing studio, because he has a recording studio....so...whatever makes him happy - after all, he built it for me, so he can call it whatever he wants !! .I call it both my studio and my sewing room. I recently took over the gym room (which was moved upstairs) to make room for my HQ Sweet Sixteen, and that room has been dubbed The Annex.....
My sister calls her sewing room Her Happy Place.